@backstage/cli-common has a possible `resolveSafeChildPath` Symlink Chain Bypass_CVE-2026-24047

6.3 / 10

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Description

Backstage is an open framework for building developer portals, and @backstage/cli-common provides config loading functionality used by the backend and command line interface of Backstage. Prior to version 0.1.17, the `resolveSafeChildPath` utility function in `@backstage/backend-plugin-api`, which is used to prevent path traversal attacks, failed to properly validate symlink chains and dangling symlinks. An attacker could bypass the path validation via symlink chains (creating `link1 → link2 → /outside` where intermediate symlinks eventually resolve outside the allowed directory) and dangling symlinks (creating symlinks pointing to non-existent paths outside the base directory, which would later be created during file operations). This function is used by Scaffolder actions and other backend components to ensure file operations stay within designated directories. This vulnerability is fixed in `@backstage/backend-plugin-api` version 0.1.17. Users should upgrade to this version or later. Some workarounds are available. Run Backstage in a containerized environment with limited filesystem access and/or restrict template creation to trusted users.

Basic Information

ID CVE-2026-24047

Source GitHub_M

Published Jan 21, 2026 at 22:45

Modified Jan 22, 2026 at 16:49

Affected Product

Vendor backstage

Product backstage

Version < 0.1.17

Affected Versions backstage backstage < 0.1.17

CWE Classification

CWE-59 CWE-61

References

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